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Paste

Selecting ``Paste'' or clicking on the main ``Paste'' button activates a small dialog box that selects what will be pasted onto what. This provides a range of options useful for stenciling, adding labels, and creating mattes and composite images. Important: Both images must be the same depth (bits/pixel).

  1. Background to transparent part of image -- copies pixels from the background into the image, only in regions of the image that are currently transparent. If transparency is ``off'', it does nothing.

  2. Background to opaque part of image -- copies pixels from the background into the image, only in regions of the image that are currently not transparent. Note that if the chromakey bit of the image is ``on'', the image will suddenly blend in with the background and seem to disappear until chromakey is turned ``off''. Conversely, if chromakey is ``off'', it copies everything behind it, obliterating the original image.

  3. Opaque part of image to background -- copies all pixels from the image onto the background unless they are transparent. This effect is identical to the main ``Paste'' button in the information area.

  4. Transparent part of image to background -- copies the original, hidden pixels from the part of the image that is transparent onto the background. If chromakey is ``off'', it does nothing.

  5. Stencil transparent part of image to background -- same as option 4, except that the pixels are all set in the current drawing color to create a stencil.

  6. Entire image to background -- copies the entire, original image onto the background, regardless of any chromakey settings.

  7. Add RGB to background - Sets the background red, green, and blue color values to be the sum of the foreground + background. A typical use would be in adding shadows. The foreground image would be thresholded, then reduced in contrast to create a gray figure on a black background. Color-invert the background, then add the foreground RGB values and color-invert the background again to create a dark shadow superimposed on the background image.

  8. Paste opaque pixels if $ >$ background - If the sum of red, green, and blue pixel values of the foreground image is greater than that of the background image, the pixels are pasted; otherwise the background is untouched.

  9. Paste opaque pixels if $ <$ background - If the sum of red, green, and blue pixel values of the foreground image is less than or equal to that of the background image, the pixels are pasted; otherwise the background is untouched.

Notes


next up previous contents index
Next: Changing size Up: Image menu Previous: Copy/Move   Contents   Index
root 2008-08-24